Method append

github-actions/browserstack/set-browserstack-env.js:12458–12465

(name, value)

          return headers;
        }
        // https://fetch.spec.whatwg.org/#convert-header-names-to-a-sorted-lowercase-set
        toSortedArray() {
          const size = this[kHeadersMap].size;
          const array = new Array(size);
          if (size <= 32) {
            if (size === 0) {
              return array;
            }
            const iterator = this[kHeadersMap][Symbol.iterator]();
            const firstValue = iterator.next().value;
            array[0] = [firstValue[0], firstValue[1].value];